Internal-combustion engine



Sept. 29, 1925.

E. BUGATTI INTERNAL comauswxon ENGINE Filed June 1 1923 Patented Sept.29, 1925.

UNITED STATES ETTORE BUGATTI, OF MOLSHEIM, FRANCE.

INTERNAL-COMBUSTION ENGINE.

Application filed June 1,

To all whom it may concern:

Be it known that I, E'rronn BUGATTI, a subject of the King of Italy, anda resident of Molsheim, Bas-Rhin Department, France, have inventedcertain new and useful Improvements in Internal-Combustion Engines; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to letters or figures of referencemarked thereon, which form a part of this specification.

The difliculty encountered in using heavy fuel (mazout, heavy oils) ininternal combustion engines of large size, has compelled the use of veryhigh compressions and to spray the fuel directly into the cylinderduring the combustion. Engines of this kind are very heavy and the partscomposing the same are submitted to considerable strains which are dueto the high compressions; on the other hand the fuel spraying devicesoperating at high temperatures and under high pressures are exposed tofrequent accidents.

The present invention relates to an engine in which heavy fuel is usedwithout the disadvantages resu ting from the high pressures in virtue ofa process of ignition allowing the engine to work like an ordinaryexplosion motor, the fuel being introduced either directly with the air,or being sprayed into the cylinder before the period of combustion.

This process of ignition consists in connecting the motor which is to bestarted with the explosion chamber of an auxiliary motor which worksalso according to a combustion cycle; a very hot and powerful flame isthus obtained which energetically stirs the mixture to be ignited andwhose action is extended to the hole of the explosion chamber, like theflame of a blowpipe, the main feature of the present inventionconsisting in the fact that the movements-of the aux iliary piston arecombined with those of the main piston through a positive drive enablingthe driving shaft to gather the motive strains transmitted through theauxiliary piston; this drive further allows, while the motor is inoperation, the position of the main piston to be varied relatively tothe driving piston so as to obtain a variation of the sparking orignition point.

1923., Serial No. 642,813.

The accompanying drawing shows a transverse vertical section of anengineembodying the invention.

According to the invention, there is adconstituted by two differentparts connected together through pipes.

The two cylinders are connected by a channel 0 in which is provided avalve C which in the case represented on the drawing is driven by a cam(not shown) keyed '70 to a shaft K and acting through the medium of therod L and of the tumbler M pivoted at N. The valve C could also be anautomatic valve so arranged as to open in the direction of the maincylinder under the infiuence of the explosion in the auxiliary cylinder.In this latter case, a spring which is timed for a stress sli htly belowthe pressure of explosion in t e auxiliary c linder would prevent thelifting of the va Va before the explosion takes place. In this caseevery guarantee isafforded that the power acting upon the auxiliarypiston will not damage the same and the parts with which it isconnected, the automatic valve then acting as a safety valve.

' In the arrangement shown, the auxiliar cylinder B is fed from an inletvalve in connection with a carbureter P with a mixture which can be moreeasily ignited than the heavy mixture of the motor or still with thesame mixture and the ignition of the explosive mixture is effected b aplu J, by compression, or by any ot er we known means. Finally, thiscylinder is provided in the usual manner with an exhaust valve S.

The main motor is fed by means of its own parts, through spraying,natural suction, through the inlet valve A or any other means. Theconnection between the auxiliary pistonB and the main piston A isobtained by means of helical gears, but any other device such as levers,eccentrics, could also be used. The crank-shaft T of the main-motorcarries a helical gear D which meshes with another helical gear Ecarried from the intermediate or secondary shaft G. This shaft carriesanother helical gear F threaded in a contrary direction to the screw E.The said helical gear I! meshes with the gear H keyed to the auxiliarycrank shaft V. All these connections can be reversed and are such thatthe angular speeds of the shafts T and V will be equal.

It is clear that an axial shifting of the shaft G under the action ofthe fork X operated by the lever V and acting upon the groove Y of theshaft G will cause the crank shaft V to move with reference to the crankshaft T and accordingly changes the moment when the load of theauxiliary cylinder will be ignited and will ignite the load of the maincylinder, thus permitting the adjustment of the point of ignition of themotor through a simple displacement of the lever V.

The operation of the motor according to a four stroke or a two strokecycle and which is the same for the cylinders A and B is as follows: Atthe moment when the explosive mixture is ignited in the cylinder B, forexample by means of the plug J, or at the moment of the normalexpansion, the valve C opens. The explosion is then transmitted. to themixture contained in the cylinder A. The two pistons A B are bothdriving pistons, the driving strains of the piston B are transmitted tothe crank shaft through helical gears, whether, as in the arrangementwhich is represented, the valve C remains open during the driving periodof the main cylinder, or if this valve closes as soon as the ignition ofthe main cylinder A takes place, the explosive mixture contained in Bacting thenalone upon the piston B In any case, the ignition motor B isproducing a power which is added to that of the heavy mixture motor. I s

The cylinder B could also be ignited through compression. This way ofproceeding would not in this case show the disadvantage which is metwith in the large cylinders, whereas it is possible, without increasingtoo much the weight of the motor, to proportionate all parts of theauxiliary cylmder B so that they can easily resist the stresses due. tothe use of auto-igniting compressions.

The 1 'tion of the auxiliary motor B can also e effected throughcompression at the time of opening of the connecting valve G. In thiscase the'mixture as used in the auxiliary motor must be a light mixtureand the part G (valve, slide-valve and the like) connecting the twomotors will be driven. The compression in the small cylinder B beingvery small with reference to the one which can possibly be given to thecarburetted mixture used in the large motor, there will be at theopening of the valve 0 an overpressure in the small cylinder, which willbe more than sufiicient to ignite the mixture contained therein, theseignited gases will then ignite the heavy gases contained in the largecylinder. i

It will be understood hat the main motor could be supplied with a lightcarburetting agent and that without departing from the principle of theinvention, some detail alterations can be made thereto.

What I claim is:

1. An internal combustion engine comprising a cylinder operable with alight fuel and a cylinder operable with heavy fuel, and wherein theexplosions occurring in the cylinder operating with light fuel willcause explosions in the cylinder operating with heavy fuel, the saidengine comprising a conduit whereby the cylinder operating with heavyfuel is connected with a corresponding cylinder operating with lightfuel, a valve disposed in said conduit and so controlled as tomomentarily open to effect the ignition in a cylinder operating withheavy fuel, inlet and exhaust valves for each cylinder, a crank shaftfor the cylinder operating with heavy fuel, a crank shaft for thecylinder operating with light fuel, and adjustable means forming amechanical connection with the crank shafts whereby the power furnishedby the cylinders is constantly utilized and the variation in theposition of the piston in the cylinder operating with light fuel withreference to the position of the piston of the cylinder operating withheavy fuel can be varied to modify the moment of ignition while theengine is running.

2. An internal combustion ,engine comprising a cylinder operable with alight fuel and a cylinder operable with heavy fuel, and wherein theexplosions occurring in the cylinder operating with light fuel willcause explosions in the cylinderoperating with heavy fuel the saidengine comprising a conduit w ereby the cylinder operating with heavyfuel is connected with a corresponding cylinder operating with lightfuel, a valve disposed in said conduit and so controlled as tomomentarily open in order to effect the ignition in a cylinder operatingwith heavy fuel, inlet and exhaust valves for each cylinder, a crankshaft for the cylinder operating with heavy fuel, a crank shaft for thecylinder operating with light fuel, a worm wheel mounted upon each crankshaft, an auxiliary shaft, two worms mounted upon the latter shaft andco-operating respectively with the worm wheels, the threads of one wormbeing in a contrary direction to the threads of the other worm, andmeans for axially displacing the shaft carrying the worms, whereby thepower furnished by the cylinders is constantly utilized and thevariation in the position of the iston in the cylinder operating withlight el with reference to the position of the'piston in the cylinderoperating with heavy fuel can be varied in order. to modify the momentof ignition while the engine is running.

ried by each crank shaft, an auxiliary shaft, worm wheels on theauxiliary shaft having oppositely directed helical teeth, in mesh withthe worm wheels on the crank-shafts, and means to axially displace theauxiliary shaft to displace the relative position of the crank-shafts.

, In testimony that I claim the foregoing as my invention I have signedmy name hereto.

ETTORE BUGATTI.

